1. Field of the Invention
The present invention relates to a method of preparing allylchlorosilanes with high yield by Si—C coupling reaction by reacting an allyl chloride derivative with a hydrosilane derivative under specific reaction condition.
2. Description of the Related Art
Allylchlorosilane known as a compound efficiently increasing C3 in organic syntheses can be used as a source of an organic silicon polymer.
As a method of preparing allylchlorosilane derivatives, a method of optionally preparing allyltrichlorosilane derivatives by hydrosilylation of allyl chloride and trichlorosilane in the presence of CuCl/Et3N catalyst is disclosed (N. Furuya, T. Sukawa J. Organomet. Chem. 1975, 96, C1-C3). This synthesis method is efficient in laboratory scale reaction, but not suitable for mass production. In the reaction using CuCl/NR3 catalyst, a large amount of tertiary amine should be used as a scavanger to remove HCl that is produced as a by-product. In this case, a large amount of amine salts, as by-products, are produced, making the process for isolating allyltrichlorosilane complicated, thereby increasing the cost for recycling the amine salts.
2-Butenylchlorosilane may be prepared by hydrosilylation of a butadiene derivative (butadiene or isoprene) with a hydrosilane in the presence of a Group 10 metal catalyst. For example, (Z)-crotyltrichlorosilane may be synthesized with a yield of 84% by the reaction of trichlorosilane with butadiene in the presence of a palladium catalyst [Pd(PPh3)4] at 100° C. for 5 hours. Under the same conditions, a mixture of 2-methyl-2-butenyltrichlorosilane (82%) and 3-methyl-2-butenyltrichlorosilane (3%) may be synthesized by the reaction of trichlorosilane with isoprene at 100° C. for 6 hours (J. Tsuji, M. Hara, K. Ohno, Tetrahedron, 1974, 30, 2143). A method of preparing a mixture of 2-methyl-2-butenylchlorosilane and 3-methyl-2-butenylchlorosilane by the hydrosilylation of isoprene with a hydrosilane (HSiX3, where X3 is Cl3, MeCl2, or Me2Cl) in the presence of a platinic acid catalyst (H2PtCl6) at 165° C. has been reported (R. A. Benkesser, et. al. J. Organomet. Chem. 1978, 156, 235-244). However, since a reactant with low boiling point (butadiene b.p.: -4.4° C.; HSiCl3: 31° C.) is used in the synthesis of allylchlorosilane by hydrosilylation, a high-pressure reactor or a sealed tube is required. In addition, since an expensive palladium or platinum catalyst is used, the manufacturing costs are high.
Another method of synthesizing allylchlorosilanes with a yield of 31% by directly reacting a mixed gas of allyl chloride and HCl with metallic silicon in the presence of a copper (Cu) catalyst (with a cadmium (Cd) cocatalyst) at 260° C. has been reported (S. H. Yeon, B. W. Lee, S.-I. Kim, I. N. Jung, Organometallics, 1993, 12, 4887). This method may be continuously performed, but the yield is low.
Since these conventional methods of preparing allylchlorosilanes as described above are not suitable for mass production, the need for a method of preparing allylchlorosilane suitable for mass production is increasing.